title: [Unusual (saw-like) temperature dependence of the rate of irreversible thermoinactivation of enzymes].
abstract: An unusual ("zig-zag") temperature dependence of the rate of irreversible thermoinactivation of enzymes was observed for native and covalently modified alpha-chymotrypsin and trypsin. This dependence was characterized by alternation of plots with positive and negative apparent values of activation energy for the thermoinactivation process. A kinetic scheme which reflects the observed regularities in thermoinactivation for which the temperature-dependent conformational transition is an essential feature, is proposed. Fluorescence spectroscopy data suggest that the conformational transition predicted by the scheme is of the unfolding type. Substantial differences in thermostabilities of "high temperature" and "low temperature" conformations of enzymes may be due to different mechanisms of their irreversible thermoinactivation.
authors.forename: V A
authors.initials: VA
authors.lastname: Shikshnis
authors.forename: N Z
authors.initials: NZ
authors.lastname: Galkantaĭte
authors.forename: N S
authors.initials: NS
authors.lastname: Melik-Nubarov
authors.forename: V Iu
authors.initials: VIu
authors.lastname: Levitskiĭ
authors.forename: V I
authors.initials: VI
authors.lastname: Slepnev
authors.forename: V V
authors.initials: VV
authors.lastname: Mozhaev
mesh_terms: D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D004791:Enzyme Inhibitors; D004795:Enzyme Stability; D007700:Kinetics; D011487:Protein Conformation; D011489:Protein Denaturation; D013696:Temperature; D014361:Trypsin Inhibitors
chemical_list: D004791:Enzyme Inhibitors; D014361:Trypsin Inhibitors; D002918:Chymotrypsin
vernacular_title: Neobychnaia (piloobraznaia) temperaturnaia zavisimost' skorosti neobratimoĭ termoinaktivatsii fermentov.